Yes reflection can provide dynamic object creation(on fly ) Class anonymous = Class.forName(“CLass name”); anonymous.getInstance(); All objects are created at Runtime in java. 10 solved Runtime object creation in java [closed]
The String args[] parameter of your main method is an array of Strings which indexes can be filled when you’re executing your program from the command line. Here is how to do it in from your command line : javac GuessingGame.java // This will compile your Java code file java GuessingGame one two three // … Read more
You can do this with a String#replaceAll method: str = str.replaceAll(“-(nic|a)\\b”, “”); Regex -(nic|adm) matches a hyphen followed by nic or adm. \\b is for word boundary to make sure we don’t match unwanted text like abc. You can add more suffixes in this group that you want to be removed. solved Java regex: Multiple … Read more
If your fields are final, they must be set either on declaration or in the constructor. Once set, the compiler will throw an error when set again, because final variables are not allowed to be re-assigned. 2 solved Using a final variable in java and its implications on methods
As you have a 2-d array, you have two length values for each loop: //you have this? array[][]; for(int i = 0; i < array.length; ++i) { for(int j = 0; j < array[i].length; ++j) { //do something on array[i][j] } } solved Using two for loops to loop through a 2D array in java
You can get this done in java using any reader. e.g- BufferedReader, FileReader anything like this. public class InJava { BufferedReader br= new BufferedReader(new InputStreamReader(System.in)); // //in main() public static void main(String [] args) { Object obj= br.readLine(); } } If you are using a list use Iterator. public class InJava { List<double> lst= new … Read more
I’m not entirely sure what you want to achieve, but to get it compile, simply add implicit constructor to class a: class a { public a(int x) { System.out.println(x); } public a() { // implicit constructor } } Since b extends a and doesn’t call the super constructor, implicit constructor of a is called “behind … Read more
Change insert to : private Node insert(Node node, int data) { if (node == null) { node = new Node(data); } else { if (data <= node.data) { node.left = insert(node.left, data); } else { node.right = insert(node.right, data); } } return (node); } In eclipse : Press Ctrl + a and then Ctrl+shift+f to … Read more
Create Class With Same Package public class Hello { public void print(){ int a = 10; System.out.println(“Number is :” +a); } } Crate Class to Set the Main Method Within the Same Package of Hello Method public class Main { public static void main(String args[]){ Hello h1 = new Hello(); h1.print(); } } solved why … Read more
lets analyze a few of the the possible error messages: java.lang.OutOfMemoryError: Java heap space java.lang.OutOfMemoryError: PermGen space java.lang.OutOfMemoryError: Requested array size exceeds VM limit java.lang.OutOfMemoryError: request <size> bytes for <reason>. Out of swap space? java.lang.OutOfMemoryError: <reason> <stack trace> (Native method) Here’s the MemLeak class: package com.post.memory.leak; import java.util.Map; public class MemLeak { public final String … Read more
If you want to get the uppercase of a char, you should use Character.toUpperCase(c), not String’s toUpperCase. So, I think you might be looking for something like this: public static void main(String[] args) { String alphabet = “abcdefghijklmnopqrstuvwxyzåäö”; System.out.println(alphabet); StringBuilder sb = new StringBuilder(); for (int i = 0; i < alphabet.length(); i++) { char … Read more
Use a loop and an ExecutorService. ExecutorService executor = Executors.newCachedThreadPool(); for (int i = 0; i < count; i++) { executor.execute(new TokenStarter()); } That should recreate your code, but is not optimal. You probably want to limit the amount of threads that run concurrently: ExecutorService executor = Executors.newFixedThreadPool(desiredParallelism); solved Optimizing thread calls in Java [closed]
Here is the problem: func(no++); Let’s say no is 32. This will pass 32 to func and then increment it. Which means that you are once again calling the function with a value of 32. And when that function hits this line, it will, once again, pass that 32 to func. Hence, an infinite recursive … Read more
You need to pass it as a parameter or create a “global variable” IE you could do either of the following… public void methodOne(String string){ System.out.println(string); } public void methodTwo(){ String string = “This string will be printed by methodOne”; methodOne(string); } OR (a better solution) Create a global variable under the class declaration… public … Read more
To find out for yourself what is happening exactly, you could run your code in a debugger and step through it to see what happens step by step. This is what happens: When you create a new Derived object, the field value in the Base part is first initialized to 0. Then the constructor of … Read more